Compass



S p 934- J. c. KARNES 1,973,716

COMPASS Filgagl March 7. 1932 Invenmr James E -Karnes Att urney PatentedSept. 18, 1934 umren STATES, PATENT OFFI E 1,973,716 I' t I namesJaniesCi Kariiea United State s if, p I .nufialanrg attainment 7,19s2seiia1ltd-597,252

4 Claims. (ciieehgzzy;

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) The invention described herein may be manuin an extendedbearing 19 fast on the side wall factured and used by or for theGovernment for of the container and parallel to the bottom governmentalpurposes, without the payment to thereof. me of any royalty thereon.Upon reciprocation of the rack 17 the sleeve 13 "15; The subject of thisinvention is a compass. will be rotated and due to the action of the 60.

In a compass provision-is made for lifting the cooperating cam surfaces14 and 15 it will also needle oif of its pivot and holding it in a fixedbe displayed axially. As shown in Fig. 2 when position when theinstrument is not in use. the sleeve is at the lower limit of its axialmove- The purpose of this feature is to prevent wearment it is clear ofthe needle 11. When the ;ing of the pivot and bearing. sleeve iselevated it comes into engagement with 5;.

The present invention relates to a novel mechthe needle, lifting it fromthe pivot and secureanism for removing and holding the needle and 1ysupporting it against the cover 6. When the is designed with a view toapplying a force unisleeve is lowered it restores the needle gently toformly and smoothly in order to prevent burthe pivot, avoiding thepossibility of damage.

;ring of the pivot and indenting of the bearing. Inward movement of therod 18 is limited by 70 A further object is to provide an inexpensiveengagement of its enlarged outer end 20 with construction which willenable the casing to be the container. Outward movement is limitedsealed against the entrance of dust and moisby the engagement of stopsurfaces 21 and 22 ture. respectively complementary to the adjoining 2QTo these and other ends, the invention concam surfaces 14 and 15.

sists in the construction, arrangement and com- A carrying case 23 isformed with a pocket 24 bination of elements described hereinafter andcapable of receiving the outer end 20 of the rod pointed out in theclaims forming a part of this only when the rod is in the in position.This specification. insures the movement of the needle to inopera- 25 Apractical embodiment of the invention is tive position when the compassis placed in the 0.

illustrated in the accompanying drawing, wherecase.

m: In the modification shown in Fig. 4 the sleeve Fig. 1 is a plan viewof the improved 'com- 25 for engaging the needle is constrained againstD rotation by means of a key 26 fitting inthe arbor Fig. 2 is atransverse sectional view with the 27. The axial displacement of thesleeve is acneedle in operative position. complished by means of a lowersleeve 28 ro- Fig. 3 is a similar view showing the needle tated throughworm gearing 29. in inoperative position. In Fig. 5 a nut 30 engageablewith the needle Figs. 4, 5 and 6 are fragmentary views partis mounted ona threaded stem 31. Spur teeth ;ly in elevation and partly in section ofmodifica- 32 on the exterior of the nut are engaged by a tions of themounting. pinion 33 on a shaft 34 mounted in the bottom Referring to thedrawing by Characters of 35 of the container. The threaded engagementreference, the compass comprises a shallow cybetween the nut and stemsupplies a cam action lindrical container 5 having a transparent coversimilar to the cam surfaces 14 and 15 in the 49 6. In the form shown inFigs. 1 to 3, a support structure of Figs. 1 and 3. positioned centrallyon the bottom 7 of the con- In Fig. 6 the stem 31a is mounted for directtainer consists of an annular base or collar 8 rotation. A pin 36anchored in the bottom 35a and a reduced cylindrical arbor 9 in whichthe is engaged in a slot 37 in the nut 30a and conpivot 10 is fiXed- Theneedle 11 has the usual strains the nut to rectilinear displacement upon;jewelled bearing 12 by which it is supported on t ti of th stem,

the P I claim:

A sleeve 13 mounted on the arbor 9 has one In a compass, a container,support 1- more cam Surfaces 14 on 1175 under edge tioned centrally onthe floor of the container and adap ed to engage Simllel 0am Surfaces 15on having an enlarged base with a serrated face, a 50; t upper face ofthe 001131 AS Shown in pivot carried by the support, a needle mountedthe d awi the cam Surfaces are Provided by on the pivot, a sleevemounted on the support se atin he adjoining faces of t eve d andsurrounding the pivot, said sleeve having a collar. The sleeve isfurther provided externally Serrated edge engageable th th Serrated facewith teeth 16 dap o be engaged by a rack of the base for moving thesleeve along the pivot 55.42 011 the end of?! rod The rod is mountedaxiswhen it is rotated thereabout, teeth on the exterior of the sleeve, arod extending through the wall of the container and a rack on the rodmeshing with the teeth on the sleeve for rotating the same.

2. In a compass, a container, a support positioned centrally on'thefloor of the container and having an enlarged base with a serrated face,a pivot carried by the support, a needle mounted on the pivot, a sleevemounted on the support and surrounding the pivot, said sleeve having aserrated edge engageable with the serrated face of the base and meansfor rotating the sleeve to move the same axially along the pivot axiswhereby the needle is raised off its pivot.

3. In a compass, a container, a pivotlinj the container, a needlemounted on the pivot, members coaxial with the pivot and havingcooperating cam surfaces, and means for relatively rotating said membersto displace one of them axially into and out of engagement with theneedle.

4. The combination with a compass including a container, a pivot in thecontainer, aneedle on the pivot, and actuating mechanism projectingthrough the container and movable in and out in placing the needle 011of or onto its pivot, of a "casing for receiving the container andhaving a pocket for receiving the projecting portion of the actuatingmechanism in its ,in position and coacting with said projecting portionto deny its entry when in the on position.

JAIWES C. KARNES.

